HØRSHOLM, Denmark, May 10, 2013 — Optical thin-film maker Delta’s new line of linear variable order sorting filters features wide transmission and reflectance bands, increasing the performance of grating-based spectrometers. The company offers a linear variable long-wave pass filter and the corresponding linear variable short-wave pass filter, together with a linear variable dichroic. The filter types can be used separately, while combining the two types enables the construction of bandpass filters that can be tuned continuously with center wavelengths from 320 to 850 nm. The filters feature improved transmission level and edge steepness, and offer blocking better than OD3 over the complete reflection range. It is possible to increase the blocking to beyond OD5 by placing another linear variable filter in the series. The 60 × 15 × 3-mm filters are coated on single quartz substrates for minimal autofluorescence and high laser damage threshold, and are especially suited for applications in spectroscopy. Custom linear variable filters can also be ordered.